1. Field of the Invention
The present invention relates to the field of integrated circuits; more specifically, it relates to a method of testing and repairing memory circuits of integrated circuits by replacement of portions of the memory circuits with redundant circuits.
2. Background of the Invention
Advanced memory circuits include redundant wordlines that can be substituted for failing wordlines by fusing in order to increase yield. However, even though a memory circuit “repaired” by substitution a good redundant wordline for a “failing” wordline by selectively blowing fuses after testing, the “good” wordlines may still contain defects that can cause reliability fails. Further, the yield increase realized by this method is not necessarily maximized for best-case parametric performance but only for test specification parametric performance. Therefore there is a need for a methodology for testing and repairing memory circuits that improves reliability and increases best-case parametric performance yield.